Conventionally, as an internal circuit of an electrical connection box for an automobile, printed circuit boards with a terminal on which a plurality of terminals are mounted upright are widely used. On the printed circuit board with a terminal, soldering sections at one end of the terminals are arranged in the state of being inserted into through-holes of the printed circuit board with gaps therein without being in pressure contact. By having the soldering sections that are movably inserted into the through-holes being soldered to the through-holes, the soldering sections are connected to printed wires of the printed circuit board and the terminals are fixed to the printed circuit board. The other ends of the terminals, serving as connecting sections for connection to counterpart terminals, may have any shape such as a tuning fork shape or a tab shape, and are arranged projecting from the printed circuit board.
However, in such a printed circuit board with a terminal, when soldering the terminals to the printed circuit board, it is important to reliably position and retain the terminals at predetermined positions on the printed circuit board. Therefore, conventionally, as disclosed in JP 2003-217437A for example, terminals are positioned and retained on a printed circuit board in the state of being press-fitted into and retained by a seat preferably made of a synthetic resin.
However, when such a seat, which is preferably made of a synthetic resin, is used to retain the terminals, there is a problem that after soldering, the terminals and the printed circuit board are relatively displaced based on the difference in linear expansion coefficient between the printed circuit board and the seat, possibly causing solder cracking. Furthermore, there is a need for a separate component, that is, the seat, which needs to be retained using a jig at the time of soldering, and thus an increase in the number of constituent components and complication of the manufacturing processing are inevitable, causing the problem of a cost increase.
In order to solve the above-identified problem, a counter measure is proposed in which the soldering sections are press-fitted into the through-holes of the printed circuit board so that the terminals stand on their own on the printed circuit board, thereby eliminating the use of the seat. However, this counter measure has the problem that, when the soldering sections are press-fitted into the through-holes, an inner layer circuit of the printed circuit board may be damaged, causing a defect such as disconnection of wires of the inner layer circuit, or it may be difficult to ensure connection reliability due to the detachment of plating from the inner surfaces of the through-holes or a reduction in the amount of solder filling.
JP 2003-217437A is an example of related art.